<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title>viewport</title>
		<style>
			*{
				margin: 0;
				padding: 0;
			}

			#demo{
				width: 100%;
				height: 200px;
				background-color: pink;
				font-size: 40px;
			}
		</style>
		<!-- <meta name="viewport" content="width=device-width"> -->
		<!-- <meta name="viewport" content="initial-scale=1"> -->
		<!-- <meta name="viewport" content="width=device-width,initial-scale=1"> -->
		<!-- <meta name="viewport" content="maximum-scale=2.0"> -->
		<!-- <meta name="viewport" content="viewport-fit=cover"> -->
		
	</head>
	<body>
		<div id="demo"></div>
		<script type="text/javascript" >
			setInterval(()=>{
				console.log('@')
				const demo = document.getElementById('demo')
				demo.innerHTML = '布局：'+document.documentElement.clientWidth + '<br/>'
				demo.innerHTML += '视觉：'+window.innerWidth
			},200)
		</script>
	</body>
</html>